import java.util.*;
class Example2_5 {
  public static void main(String args[]) {
    int start = 0,end,middle;
    int a[] = {12,45,67,89,123,-45,67,20165322};
    int N = a.length;
    for(int i=0; i<N; i++) {
    for(int j = i+1; j<N ;j++) {
	if(a[j] < a[i]) {
	  int t = a[j];
	  a[j] = a[i];
	}
      }
    }
    Scanner scanner = new Scanner(System.in);
    System.out.println("输入整数，程序判断该整数是否在数组中：");
    int number = scanner.nextInt();
    int count = 0;
    end = N;
    middle=(start+end)/2;
    while(number!=a[middle]){
	if(number>a[middle])
	  start = middle;
	else if(number<a[middle])
	  end = middle;
	middle = (start+end)/2;
	count++;
	if(count>N/2)
	  break;
    }
    if(count>N/2)
      System.out.printf("%d 不在数组中 .\n",number);
    else
      System.out.printf("%d 在数组中 .\n",number);
  }
}
